1. Field of the Invention
The present invention relates to an optoelectronic sensor device for sensing the wetting of a transparent motor vehicle windshield having precipitation in which the sensor device includes a radiation emitter and a radiation detector arranged on a first circuit support, beam shaping means for parallelizing and directing optical radiation emitted by the emitter toward the windshield and for focusing and directing the radiation toward the detector after the radiation has reflected off the windshield, and a coupling element for coupling the radiation into and out of the windshield.
2. Background Art
DE 101 04 653 A1 discloses an optoelectronic sensor device of this type. The sensor device includes a radiation conductor and a coupling element. The radiation conductor has a radiation exit surface and a radiation entrance surface. The coupling element is attached to the inside surface of a windshield. The coupling element has profiles which have radiation in-coupling areas on first sides and radiation out-coupling areas on second sides. The radiation in-coupling areas are oriented parallel to the radiation exit surface of the radiation conductor. The radiation out-coupling areas are oriented parallel to the radiation entrance surface of the radiation conductor. The profiles make it possible to do without direct coupling of the radiation conductor to the inside windshield surface.
In order to allow optimal use of the radiation beam cross-section with several different windshield thicknesses, and to do so without changing the structure of the radiation conductor, the sensor device includes means for adjusting the position of the radiation conductor relative to the windshield. As such, the position adjusting means adjust the distance of the radiation entrance and exit surfaces of the radiation conductor relative to the inside windshield surface. In this sensor device, the position adjusting means are on the radiation conductor itself and/or on a base which holds the radiation conductor in position relative to the windshield.